crypto/nx: Add P9 NX specific error codes for 842 engine

This patch adds changes for checking P9 specific 842 engine
error codes. These errros are reported in coprocessor status
block (CSB) for failures.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>